During the past 31 months, the number of drivers aged 70 or above has leapt by 323,631 - a monthly increase of 10,440.

And the number of drivers aged 80 or above has broken the one million barrier for the first time. The UK's oldest driver is 107.

The IAM's chief executive Sarah Sillars says that because people are living longer there are many more older motorists on the roads.

"We want these drivers to enjoy their motoring for as long as possible, so we want some thought and resources to go into how we can make this happen," she says.

Research by the IAM shows the most common reasons for collisions involving older drivers are failing to judge others' direction or speed, poor manoeuvres, losing control, illness or disability, dazzling sun, nervousness, panic or anxiety.

To improve safety, the organisation is calling for a plan that includes looking into how vehicle design and in-car tech can help the over-70s and ways in which more information can be provided for them.

It says there should also be more online assessment tools for older drivers, more voluntary on-road assessment and improved co-operation between driving agencies.